Paper manufacture



June 21, 1932.

H. T. RUF F PAPER MANUFACTURE Filed April 14. 1930 Patented June 21,1932 UNITED STATI- 2s PATENroFFlcE HAROLD T. BUFF, OIF CHILLICOTHE,OHIO, ASSIG'NOB. TO THE MEAD RESEARCH4 ENGINEERING COMPANY, OF DAYTON,OHIO, A CORPORATION F OHIO PAPER HANUFACTURE Application led April 14,

This invention relates to the manufacture of paper, and particularly tothe treatment of fibrous material in the roduction of pulp.

One of the principal o jects of the inven- 5 tion is to provide a'method for efectlvely and economically treating fibrous material with ahalogenating agent in the manufacture of ul p Aliiother object of thisinvention is to provide a method of chlorinating fibrous material athigh consistency with a gaseous chlorinating agent, which permits ofcontrolled and effective treatment, with high economy in the 'use of thechlorinating agent.

Still another object of the invention isto provide apparatus forcarrying out the above method, which apparatus is simple inconstruction, highly efective in operation, providing accurate controlwith a uniform production of treated fibrousI material, while insuringagainst the escape of objectionable fumes. y

Other objects and advantages of the invention will be apparent from thefollowing description when taken in connection with the accompanying.drawing and appended claims.

In the drawing, the single gure is adiagrammatic elevational view,partly in section. of apparatus: constructed for carrying out the methodof this invention.

The invention isl appliible to the chlorinating treatment of, fib'ro yniaterials generally, such as wood, fst fibrous grasses and analogousmateria the manufacture of pulp or analogousmaterials? 'ItQissuitablefor the treatment- "ghiyiignified fibrous material, andi- I i p only forbleaching, butfalso as aplllfping step in the disintegrationofundefibered material. For example','f which has been given apreliminar plete or partial digestion orsteeping. to iucompletely removenon-fibrousibon constituents, can then be subjectedgtfrthe treatment ofthis invention 'to effect pulping and removal of such,vnon.fi.bro1' con#stituents. The invention`- is also, applicable generally for bleachingpulp orfibrous material, Aor for any pulpinglor bleaching propermanipulation of the valves Q6.

r The presentv invention is particularly adapted for the treatment offibrous material i v[with a gaseous halogenating'agent, such asvgfclhlorine gas. For themosteffective opera- 1930. serial No. 444,075.

process involving gas chlorination as a `step thereof.

Referring to the drawing, in which a preferred embodiment of theinvention is illustrated, a plurality of chlorinating chambers aremounted in alignment, four chambers being shown at 10, 11, 12 and 13respectively. Each chamber comprises a shell constructed of acid proofymaterial such as tile, the size of the shell depending upon `thedesired capacity of 'the particular plant and the number of chambersused. The shell is provided with an opening 11 in the upper portionthereof closed by a removable cover 12. Preferably the cover 12 is watersealed, such a5 as by providing flanges 13 and 14 on the top of thechamber to form an annular basin for containing a sealing liquidwithinwhichv the cover 12 dips. Fibrous stock to be treated is supplied from abin or storage tank14 through thechute 15 to a conveyor 16, shown as anopen trough -17 having mounted therein a longitudinal shaft 18 driven bya pulley or gear 19 from any suitable source of power, the shaftcarrying a helical screw 20 for progressively feeding the brous materialalong the trough. The commori conveyor 16 is arranged above thechlorinating chambers 10-13 in alignment therewith, and is provided atspaced points with a plurality of downwardly depending chutes 21-24adapted to introduce the fibrous ma-l terial into the several chambers10-13 when the respective covers 12 .are removed. Each chutecommunicates with trough 17 by an 85 opening 25 in the bottom wallthereof, this opening being controlled by a suitable slide valve 26. sothat the fibrous materialmay be selectively fed to each` of the chambersby tion, the fibrous material is preferably`sup= im`Y fp'lied at a highconsistency such as to be readily permeable to gas. For example, fibrousmaterial, or pulp stock, at a consistency in excess/of 15% gives verysatisfactory results. This material is readily handled by the screw formdistribution of the chlorinating agent through the fibrous materialtherein.

Gas oiftakes 42-45 having respective control valves 46-49 communicatewith a common suction main 50 leading to a suitable source of suctionsuch as a suction pump 51. Each of the gas oiftakes preferablycommunicates with the upper portion of its respective chlorinatingchamber, so that the introduction of chlorine gas into the fibrousmaterial may be assisted by connecting the re a spective oiftake at theupper portion of the chamber to the suction pump 51, whereby the airwithin the chamber is exhausted and the chlorine gas uniformlyintroduced in a rising column within the chamber.

The respective chlorinating chambers are also provided with pipeconnections 52-55 having respective control valves 56-59 communicatingwith the lower portions of each of the chlorinating vchambers andconnecting to a common by-pass main 60. dEach chamber is also provided,preferably adjacent the upper end thereof, with a pipe 62 controlled bya suitable valve 63 which opens to atmosphere or communicates with asuitable source of inert Iiuid, such as a gas or vapor which does notobjectionably react with the chlorinated material or pulp. Adjacent thelower end thereof, each chamber is provided with a pipe 65 controlled bya valve 66 communicating with a source of water or other suitableslushing liquid under pressure.

In operation, assuming the chamber 10 is to be supplied with fibrousmateria-l, the cover 12 is removed and the valve 26 opened, so that theoperation of the screw conveyor 16 serves to feed fibrous materialthrough chute 21 into the chamber 10 until it is substantially filled.The cover 12 is then replaced, valve 26 closed, and then the cover 12 ofanother chamber such as chamber 11 is removed and the valve of chute 22opened so that fibrous material may then be supplied to this chamberwhile the chlorinating operation proceeds in chamber 10. This isaccomplished by opening valves 31, 36 and 46, so that the chamber 10 isconnected to the suction pump'and to the chlorine gas main, the chlorinegas thus being drawn into the chamber` through 'the perforateddistribution pipe 40 until the level of the gas appears above thefibrous material within the chamber, as can be determined by a suitablesight glass or gage. It is not essential that the chamber be connectedto the suction pump during the introduction of the chlorine ygas orother' chlorinating agent, but this is preferred in order to minimizethe danger of gas leakage. The fact that the chlorine is drawn into thechamber under subatmospherie pressure insures against escape of gas fromthe chamber with resultant contamination of the surrounding atmosphere.,When the chamber is properly lled or supplied with chlorinating gas, thevalves 36 and 46 are then closed, and the chamber 10 allowed to standfor a suitable time, such as about 2O minutes, to permit thechlorinating action to proceed to substantial completion. Sufficientchlorine gas is supplied to the chamber to insure the substantiallycomplete chlorination of the fibrous material therein.

In the meantime, chamber 11 has been filled with fibrous material andthe cover of this chamber replaced, chamber 12 then being supplied andfilled with the fibrous material, so that substantially continuousoperation of the screw conveyor and the continuous and uniform feedingof the fibrous material from the common conveyor to one of the chambersis secured. Valves 56, 57v and 47 are then opened, so that chamber 11 isconnected with suction main by the offtake 43, and the lower portions ofchambers 10 and 11 are connected with each other through the by-passmain 60. At this time, valve 63 is also opened so that an inertfiuidsuch as air is drawn into the upper portion of chamber 10 throughthe pipe connection 62, or this may be permitted by loosening the cover12 and permitting air to pass in around the loosened cover. The suctionpump 51 then draws this air down through the fibrous material within thechamber 10, serving to drive. out excesschlorine gas remaining in thematerial, the mixed -air and excess chlorine gas passing through theby-pass main into the lower portion of the chamber 11. This mixed gas isthen drawn up through the fresh untreated fibrous material within:chamber 11, so that the chlorine gas contained in this gaseous mixtureis absorbed by and reacts with the fibrous material therein.

As the reaction of the fibrous material with chlorine gas is very rapid,substantially all of the chlorine in this gaseous mixture isimmediatelyl absorbed by and used in reaction with the fibrous material.Thus the excess chlorine gas is effectively removed from the treatedfibrous material in chamber 10, and economy is secured by the use o fthis gas in treating additional fibrous material in chamber 1:1. Theremaining air and otherfiuid passes through the offtake 43 to thesuction main 50 and is discharged to atmosphere or suitable main. Thiswashing of the treated previouslv described for chambers 10 and l1.

Y Lenaweev fibrous material in chamber 10 is continued untilsubstantially all the excess chlorinating agent is removed therefrom.The valves 63, 56 and 57 are then closed, and the valve 37 is opened, sothat additional chlorine gas is supplied from main 30 to thedistribution pipe 40 of chamber 11 until this chamber is supplied withthe desired quantity of chlorine gas for the completion of thechlorinating action therein.

Valve 66 is opened in the meantime to permit water or other slashingliquid to be introduced into the lower portion of chamber 10 to dilutethe treated stock therein and to slush it out through a dischargeopening 70 controlled by a suitable valve 71 in the base of the chamber.Preferably the discharge 70` is also water sealed during operation,which may be conveniently accomplished by the provision of a small waterpipe 71 for introducing a small amount of water above the valve 71 priorto the chlorinating operation. The fibrous material of high consistencywithin the chamber 10 moves downwardl therein by gravity as material atthe bottom is slushed out from the chamber. This diluted stockdischarges through a suitable chute 72 into an inclined trough 72 whichextends longitudinally beneath the several chlorinating chambers. Thedischarge openings 7() of these several chambers, which are controlledby valve 71 vin the manner 'of chamber 10, also feed through suitablechutes 72 into the trough 73, so that a common discharge conveyor ortrough receives the treated material discharged from the severallchambers and leads this material to a suitable stock chest (not shown).

During the emptying of the chamber 10, the chlorination of the fibrousmaterial in chamber 11 proceeds to completion, while chamber 12 isfilled with fibrous material or stock to be treated. The valves 37 and47 having been closed when sufficient chlorine has been introduced intochamber 11, then at the completion of the chlorinating action therein,the valves 57 58 and 48 are opened and also valve 63 of chamber 11. sothat air is drawn into and through the fibrous material within chamber11 to wash out the excess chlorine gas from the fibrous materialtherein, the mixed air and chlorine gas passing through the by-pass main60l into the lower portion of chamber 12 in the manner During this time.chamber 13 is being filled with fresh fibrous material, while theemptying' operation of chamber 10 is being completed. This operation isthen repeated for chambers 12 and 13, so that the excess Chlorine gaswashed out of the fibrous material in chamber 12 is absorbed by andreacts with the fibrous material 'in chamber 13; and then in the nextstage of'operations chambers 10 and 13 are connected by the by-pass main60 so that the excess chlorine gas'i'washed out While a smaller orlarger number of chlorinating chambers can 'of course be used,preferably 'at least four such chambers are connected in a unit asshown, so that two of the chambers may be connected through the bypassmain for washing action. of the'chlorinating material in one chamber andthe absorbing of the excess chlorine gas driven off of that material bythe additional fibrous material in the other chamber, the third chamberat this time being emptied of treated fibrous material, and the fourthchamber being filled. A substantially continuous supply of the fibrousmaterial to one of the chambers is thus permitted by the common feedingconveyor 16, and a uniform discharge of treated fibrous material fromone of the y chambers is received during operation by the trough 7 3 andsupplied to a stock chest for further treatment. vOther suitable gaseoushalogenating 0r chlorinating agents can be used in accordance with thisinvention, such as gaseous bromine, or chlorine gas mixed with othergases. For example. a mixture of chlorine and air may be used to give aless active chlorinating reaction.

This invention thus provides a convenient means of treating shredded orcooked lignified fibrous material, or pulped material, with a gaseoushalogenating agent to effect further pulping, or bleaching, or bothpulping and bleaching. The use of a non-halogenating agent such as airin order to displace the excess gaseous halogenating agent such aslgaseous chlorine. is found an effective means of washing the pulpwithout the necessity of liquid washing. or the employment of apparatusother than tbe chlorinating chamber which can be satisfactorily lined ormade of acid-proof material to resist corrosion.

Such air washing very efciently removes excess chlorinating agent,leaving at most only a. very small Quantity which is absorbed bv thepulp in a short reaction time. Any small residual ouantity of freechlorine left in the pulp can be neutralized bv the addition of a smallamount of some suitable anti-Chlor in the well known manner. In thismanner, itis possible to insure that no free chlorine remains in thepulp adlnixed with the reaction products of the chlorination. which`reaction productsfcontain a large percentage of hydrochloric acid. Suchmixture of reaction products with free chlorine produces a very f.

objectionable free chlorine is effectively`elimiuated from the pulp andreaction products prior to removal from the chlorination chamber. thusrendering the subsequent treatment free from corrosion ('lifficulties.The preliminary treatment of lignified fibrous material with chlorinegas substantially diluted with air has the advantagl;l of providing forcontrol of the chlorination reaction,` avoiding objectionable localoverheating with consequent iniury of the cellulose.l fibers. After thepreliminary incomplete chlorination in this manner. the fibrous materialcan then be treated with more concentrated or substantially purechlorine gas Without objectionable results'. providing for thecompletion of the chlorinating reaction in an effective manner. Theprocess provides for the use of an excess of chlorine for the finalchlorinating step. and at the same time provides for economicalutilization of this excess of the chlorinating agent withoutnecessitating an elaborate recovery system.

lVhile the method herein described, and the form of apparatus forcarrying this method into effect. constitute preferred embodiments ofthe invention, it is to be understood that the in-yention is not limitedto this precise method andform of apparatus. and that changes may bemade in either Without departing from the scope of the invention whichis defined in the appended claims.

lVhat is claimed is:

l. In the manufacture of pulp, the method which comprises subiectingfibrous material to treatment with a halogen, then-passing a fiuidthrough the treated fibrous material to drive out excess halogen, andpassing the mixed fluid and halogen discharging from said fibrousmaterial through additional fibrous materi alto thereby use the excesshalogen in treating the additional fibrous material.

2. In the manufacture of pulp, the method which comprises subjectingfibrous material to treatment with a gaseous halogen. then passing afluid through the treated fibrous material to drive out-excess halogen,passing the mixed fiuid and halogen discharging from said fibrousmaterial through additional fibrous material to thereby use the excesshalogen in treating the additional fibrousV tional fibrous materialtothereby use the excess halogen in treating the additional fibrousmaterial` continuing thc passing of the `fiuid until the first mentionedfibrous material is substantially free of excess halogen, thenintroducing a liquid into the first mentioned fibrous material to dilutethis material and to slush it out of the treating zone, and subjectingthe additional fibrous material to further treatment with a gaseoushalogen.

4. In the manufacture of pulp, the method which comprises subjectingfibrous material at a high'consistency such as to be readily permeableto gas to treatment with chlorine gas, then passing air through thetreated fibrous material to drive out excess chlorine gas therefrom. andpassing the mixed air and excess chlorine gas discharged from thetreated fibrous material through additional fibrous material to therebyuse the excess chlorine gas in the treatment of the additional fibrousmaterial.

5. In the manufacture of pulp, the method which comprises subjectingfibrous material at a high consistency such as to be readil;1 permeableto gas to treatment with chlorine gas, then passing air through thetreated fibrous material to drive out excess chlorine gas therefrom, andpassing the mixed air and excess chlorine gas discharged from thetreated fibrous material through additional fibrous material to therebyuse the excess chlorine gas in the treatment of the additional fibrousmaterial` continuing the passing of the. air until the first mentionedfibrous material is substantially free of excess chlorine gas. thenremoving the first mentioned treated material. and subiecting the.additional fibrous material to further treatment with chlorine gas.

6. Apparatus of the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers. means for supplying fibrous material thereto. means forsupplying a halogenating agent to one of said chambers. means forsupplying a Washing fluid to said chamber to drive off excesshalogenating agent from the fibrous material therein, an oft'take forthe mixed Washing fluid and excess halogenating agent driven ofi' fromsaidchamber, and a connection communicating with said offtake forintroducing said mixed Washing fiuid and said halogenating agent intoaseoond chamber into contact with fibrous material therein.

7. Apparatus of the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers, means for supplying fibrous material thereto, means forsupplying a gaseous halogenating agent to one of said chambers, meansfor supplying a washing fiuid to said chamber to drive off;` excesshalogenating agent from the fibrous material therein, anpotake for themixed washing fluid and excess halogenating agent driven ofi from saidchamber, a connection communicatin with said offtake for introducingsaid mixed washing iiuid and said halogenating a ent into a secondchamber into contact with firous material therein, means for the removalof treated fibrous material from said first mentioned chamber, and meansfor supplying additional gaseous halogenating agent to said secondchamber.

8. Apparatus of the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers, means for supplying fibrous material thereto, means forintroducing a halogenating agent to one of said chambers, means forsupplying an inert gas to said chamber to drive off excess halogenatingagent from the fibrous material therein, an otake for the mixed inertgas and excess halogenating agent driven o from said chamber, aconnection communicating with said offtake for introducing said mixedinert gas and excess halogenating agent into a second chamber intocontact with fibrous material therein, means for introducing'a liquidinto said first mentioned chamber to slush out treated materialtherefrom, and means for supplying additional halogenating agent to saidsecond chamber.

9. Apparatus of the character described adapted for the treatment offibrous material in Vthe manufacture of pulp, comprising a plurality ofchambers, means for introducing brous material into each of saidchambers, valve controlled inlets for the introduction of chlorine gasinto each of said chambers, valve controlled offtakes for each of saidchambers, suction means connected to said offtakes, means forintroducing air into one of said chambers, and a connection between saidiirst chamber and a second chamber, whereby said suction means isadapted to draw air into said first chamber and through the treatedfibrous material therein to wash out excess chlorine gas from saidfibrous material, the mixed air and excess chlorine gas then being drawnthrough said connection into said second chamber and into Contact withfibrous material therein, the remaining fluid passing through theofi'take of said second chamber to said suction means.

l0. Apparatus of the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers,.means for introducing brous material into each of saidchambers, valve controlled inlets for the introduction of chlorine gasinto each of said chambers, valve controlled oitakes communicating withthe upper portions of each of said chambers, suction means connected tosaid -oii'takes, means for introducing air adjacent the upper portion ofone of said chambers,

and a connection between the lower portion of said one chamber and thelower portion of a second chamber, whereby said 'suction means isadapted -to draw air into said first chamber `and through the treatedfibrous material therein to wash out excessl chlorine gas from saidfibrous material, the mixed air and excess chlorine gas then being drawnthrough said connection into said second chamber and into contact withfibrous material therein, the remaining fluid passing through theofftake of' said second chamber to said suction means.

11. Apparatusof the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers, a common supplying meansfor fibrous material, means forselectivelycontrolling the feeding of fibrous material from said commonsupplying means to each of said chambers, a common maln for halogenatingagent, and means for selectively controlling the supplying ofhalogenating agent from said main to each of said chamers.

12. Apparatus of the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers, means for sup lying fibrous material to each of said chambers,a common chlorine gas main, means for selectively controlling thesupplying of chlorine gas from said main to'ea-ch of said chambers, acommon suction main, a suction means therein, and means for selectivelycontrolling communication of each of said chambers with'said commonsuction main.

13. Apparatus of the character described adapted for the treatment ofbrous material in the manufacture Ofpulp, comprising a plurality ofchambers, means for supplying fibrous material to each of said chambers,a common chlorine gas main, means for selectively controlling thesupplying of chlorine gas from said main to .each of said chambers,

a common suction main, a suction means therein, means for selectivelycontrolling communication of each of said chambers with said commonsuction main, means for selectively introducing air into each of saidchambers, 'and means for the passage of gaseous products from one ofsaid chambers to another.

14. Apparatus of the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers, means for supplying fibrous material to each of said chambers,a common chlorine gas main, means for selectively controlling thesupplying of chlorine gas from said main to each of said chambers, acommon suction main, a suction means therein, means for selectivelycontrolling communication of each of said chamberswith said commonsuction main, means for selectively introducing air into each of saidchambers, a common by-pass main, and valve controlled connectionsbetween each ofv said chambers and said by-pass main,

15. Apparatus of the character described adapted for the treatment offibrous material in the manufacture of pulp, comprising a plurality ofchambers, a common supplying means for fibrous material, means forselectively controlling the feeding of fibrous mateP rial from saidcommon supplying means to each of said chambers, a common chlorine gasmain, means for selectively controllingthe supplying of chlorine gasfrom said main to each of sald chambers, a common suction main, asuction means therein, means for selectively controlling communicationof each of said chambers with said common suction main, means forselectively introducing air into each'of said chambers, a common bypassmain, valve controlled connections between each of said chambers andsaid b -pass main, and means for removing treated brous material fromeach of said chambers.

16. Apparatus of the character described ada ted for thetreatment-ofiibrous material in t e manufacture-of pulp, comprising atleast vfour chambers, means for suppl ing fibrous material to each ofsaid cham ers, means for selectively supplying gaseous chlorine to saidchambers, means for selectively introducing air into said chambers,means for passing gaseous products from one of said chambersto another,and means for removing treated fibrous material from each of saidchambers, the arrangement be' such that two of said chambers areadapteto be placed in communication so that air and excess chlorine gas ma bepassed from the treated fibrous materia in one chamber into theuntreated fibrous material in another the 'treating the said l ,excessof moreconcentrated chlorine gas to -the removed excess of chlorine 1nwith a chlorine gas admixed with a substani `tial proportion of air as adiluent, and subsequently treating the fibrous material with asubstantially more concentrated'chlorine as. 20. In the manufacture ofulp, the met 10d which comprises treating Ebrous material with an excessof a gaseous halogenating agent, so that at the completion of thehalogenating reaction a substantial amount of the aseous halogenatingagent remains in brous ,material, removm such excess halogenating a ntin gaseous orm from the p fibrous materia and passing removed gaseoushalo natin agent'into reaction contact with ad tional brous materiah 21.Inthe manufacture of pul the meth which com rises first treatin brousmaterial with c orine as dilute with air, then brous material with ancomplete ythe chlorinat'ing reaction, removing the excess chlorine 1ngaseous form from the chlorinated fibrous material, and passing forminto lcontact with additional fibrous material.

In testimony whereof I hereto aiiix my signature. Y

Y HAROLD T. RUFF.

chamber, while a, third chamber is bein sup- .i

gulp, the method which comprises treating brous material with a gaseoushalogenatingagent'admixed with a substantial proportion of anon-halogenating aseous diluent, and subsequently treating t e fibrousmaterial with a more concentrated gaseous halogenating agent. 18. In themanufacture of 1plulp, the method which' comprises treating brousmaterial with a gaseous halogenating agent admixed with a substantialproportion'of a non-halogenating gaseous diluent, the quantity ofgaseous halogenating agent used in this treatment being insufficient toeffect complete halogenation of the librous material, and` subsequentlycompleting the halogenating of the fibrous material by treatment with anexcess of a more concentrated gaseous halogenating agent.

19. In the manufacture of pulp, the method i `which comprises treatingfibrous material gaseous Ifil-

